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Favero JD, Luck C, Lipp OV, Nguyen AT, Marinovic W. N1-P2 event-related potentials and perceived intensity are associated: The effects of a weak pre-stimulus and attentional load on processing of a subsequent intense stimulus. Biol Psychol 2023; 184:108711. [PMID: 37832864 DOI: 10.1016/j.biopsycho.2023.108711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 10/09/2023] [Accepted: 10/09/2023] [Indexed: 10/15/2023]
Abstract
A weak stimulus presented immediately before a more intense one reduces both the N1-P2 cortical response and the perceived intensity of the intense stimulus. The former effect is referred to as cortical prepulse inhibition (PPI), the latter as prepulse inhibition of perceived stimulus intensity (PPIPSI). Both phenomena are used to study sensory gating in clinical and non-clinical populations, however little is known about their relationship. Here, we investigated 1) the possibility that cortical PPI and PPIPSI are associated, and 2) how they are affected by attentional load. Participants were tasked with comparing the intensity of an electric pulse presented alone versus one preceded 200 ms by a weaker electric prepulse (Experiment 1), or an acoustic pulse presented alone with one preceded 170 ms by a weaker acoustic prepulse (Experiment 2). A counting task (easy vs. hard) manipulating attentional load was included in Experiment 2. In both experiments, we observed a relationship between N1-P2 amplitude and perceived intensity, where greater cortical PPI was associated with a higher probability of perceiving the 'pulse with prepulse' as less intense. Moreover, higher attentional load decreased observations of PPIPSI but had no effect on N1-P2 amplitude. Based on the findings we propose that PPIPSI partially relies on the allocation of attentional resources towards monitoring cortical channels that process stimulus intensity characteristics such as the N1-P2 complex.
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Affiliation(s)
- Jaspa D Favero
- School of Population Health, Curtin University, Perth, Western Australia, Australia.
| | - Camilla Luck
- School of Population Health, Curtin University, Perth, Western Australia, Australia
| | - Ottmar V Lipp
- School of Psychology & Counselling, Queensland University of Technology, Brisbane, Queensland, Australia
| | - An T Nguyen
- School of Population Health, Curtin University, Perth, Western Australia, Australia
| | - Welber Marinovic
- School of Population Health, Curtin University, Perth, Western Australia, Australia.
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2
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Tics: neurological disorders determined by a deficit in sensorimotor gating processes. Neurol Sci 2022; 43:5839-5850. [PMID: 35781754 PMCID: PMC9474467 DOI: 10.1007/s10072-022-06235-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 06/20/2022] [Indexed: 11/21/2022]
Abstract
Tic related disorders affect 4–20% of the population, mostly idiopathic, can be grouped in a wide spectrum of severity, where the most severe end is Tourette Syndrome (TS). Tics are arrhythmic hyperkinesias to whom execution the subject is forced by a “premonitory urge” that can be classified as sensory tic, just-right experience or urge without obsession. If an intact volitional inhibition allows patients to temporarily suppress tics, a lack or deficit in automatic inhibition is involved in the genesis of the disorder. Studies have assessed the presence of intrinsic microscopic and macroscopic anomalies in striatal circuits and relative cortical areas in association with a hyperdopaminergic state in the basal forebrain. Prepulse inhibition (PPI) of the startle reflex is a measure of inhibitory functions by which a weak sensory stimulus inhibits the elicitation of a startle response determined by a sudden intense stimulus. It is considered an operation measure of sensorimotor gating, a neural process by which unnecessary stimuli are eliminated from awareness. Evidence points out that the limbic domain of the CSTC loops, dopamine and GABA receptors within the striatum play an important role in PPI modulation. It is conceivable that a sensorimotor gating deficit may be involved in the genesis of premonitory urge and symptoms. Therefore, correcting the sensorimotor gating deficit may be considered a target for tic-related disorders therapies; in such case PPI (as well as other indirect estimators of sensorimotor gating) could represent therapeutic impact predictors.
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3
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Proshin AT. Comparative Analysis of Dopaminergic and Cholinergic Mechanisms of Sensory and Sensorimotor Gating in Healthy Individuals and in Patients With Schizophrenia. Front Behav Neurosci 2022; 16:887312. [PMID: 35846783 PMCID: PMC9282644 DOI: 10.3389/fnbeh.2022.887312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 06/01/2022] [Indexed: 11/13/2022] Open
Abstract
Sensory and sensorimotor gating provide the early processing of information under conditions of rapid presentation of multiple stimuli. Gating deficiency is observed in various psychopathologies, in particular, in schizophrenia. However, there is also a significant proportion of people in the general population with low filtration rates who do not show any noticeable cognitive decline. The review article presents a comparative analysis of existing data on the peculiarities of cholinergic and dopaminergic mechanisms associated with lowering gating in healthy individuals and in patients with schizophrenia. The differences in gating mechanisms in cohorts of healthy individuals and those with schizophrenia are discussed.
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Yang X, Liu L, Yang P, Ding Y, Wang C, Li L. The Effects of Attention on the Syllable-Induced Prepulse Inhibition of the Startle Reflex and Cortical EEG Responses against Energetic or Informational Masking in Humans. Brain Sci 2022; 12:brainsci12050660. [PMID: 35625046 PMCID: PMC9139428 DOI: 10.3390/brainsci12050660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 05/09/2022] [Accepted: 05/15/2022] [Indexed: 11/29/2022] Open
Abstract
Prepulse inhibition (PPI) is the reduction in the acoustic startle reflex (ASR) when the startling stimulus (pulse) is preceded by a weaker, non-starting stimulus. This can be enhanced by facilitating selective attention to the prepulse against a noise-masking background. On the other hand, the facilitation of selective attention to a target speech can release the target speech from masking, particularly from speech informational masking. It is not clear whether attentional regulation also affects PPI in this kind of auditory masking. This study used a speech syllable as the prepulse to examine whether the masker type and perceptual spatial attention can affect the PPI or the scalp EEG responses to the prepulse in healthy younger-adult humans, and whether the ERPs evoked by the prepulse can predict the PPI intensity of the ASR. The results showed that the speech masker produced a larger masking effect than the noise masker, and the perceptual spatial separation facilitated selective attention to the prepulse, enhancing both the N1 component of the prepulse syllable and the PPI of the ASR, particularly when the masker was speech. In addition, there was no significant correlation between the PPI and ERPs under any of the conditions, but the perceptual separation-induced PPI enhancement and ERP N1P2 peak-to-peak amplitude enhancement were correlated under the speech-masking condition. Thus, the attention-mediated PPI is useful for differentiating noise energetic masking and speech informational masking, and the perceptual separation-induced release of the prepulse from informational masking is more associated with attention-mediated early cortical unmasking processing than with energetic masking. However, the processes for the PPI of the ASR and the cortical responses to the prepulse are mediated by different neural mechanisms.
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Affiliation(s)
- Xiaoqin Yang
- Collaborative Innovation Center for Brain Disorders, Laboratory of Brain Disorders, Beijing Institute of Brain Disorders, Capital Medical University Ministry of Science and Technology, Beijing 100069, China;
| | - Lei Liu
- Key Laboratory on Machine Perception (Ministry of Education), Beijing Key Laboratory of Behavior and Mental Health, School of Psychological and Cognitive Sciences, Peking University, Beijing 100080, China; (L.L.); (P.Y.); (Y.D.)
| | - Pengcheng Yang
- Key Laboratory on Machine Perception (Ministry of Education), Beijing Key Laboratory of Behavior and Mental Health, School of Psychological and Cognitive Sciences, Peking University, Beijing 100080, China; (L.L.); (P.Y.); (Y.D.)
| | - Yu Ding
- Key Laboratory on Machine Perception (Ministry of Education), Beijing Key Laboratory of Behavior and Mental Health, School of Psychological and Cognitive Sciences, Peking University, Beijing 100080, China; (L.L.); (P.Y.); (Y.D.)
- Division of Sports Science and Physical Education, Tsinghua University, Beijing 100084, China
| | - Changming Wang
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China;
| | - Liang Li
- Collaborative Innovation Center for Brain Disorders, Laboratory of Brain Disorders, Beijing Institute of Brain Disorders, Capital Medical University Ministry of Science and Technology, Beijing 100069, China;
- Key Laboratory on Machine Perception (Ministry of Education), Beijing Key Laboratory of Behavior and Mental Health, School of Psychological and Cognitive Sciences, Peking University, Beijing 100080, China; (L.L.); (P.Y.); (Y.D.)
- Correspondence:
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Ku Y, Kim DY, Kwon C, Noh TS, Park MK, Lee JH, Oh SH, Kim HC, Suh MW. Effect of age on the gap-prepulse inhibition of the cortical N1-P2 complex in humans as a step towards an objective measure of tinnitus. PLoS One 2020; 15:e0241136. [PMID: 33152745 PMCID: PMC7644010 DOI: 10.1371/journal.pone.0241136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 10/08/2020] [Indexed: 11/18/2022] Open
Abstract
The gap-prepulse inhibition of the acoustic startle reflex has been widely used as a behavioral method for tinnitus screening in animal studies. The cortical-evoked potential gap-induced inhibition has also been investigated in animals as well as in human subjects. The present study aimed to investigate the effect of age on the cortical N1-P2 complex in the gap-prepulse inhibition paradigm. Fifty-seven subjects, aged 20 to 68 years, without continuous tinnitus, were tested with two effective gap conditions (embedded gap of 50- or 20-ms duration). Retest sessions were performed within one month. A significant gap-induced inhibition of the N1-P2 complex was found in both gap durations. Age differently affected the inhibition, depending on gap duration. With a 50-ms gap, the inhibition decreased significantly with the increase in age. This age-inhibition relationship was not found when using a 20-ms gap. The results were reproducible in the retest session. Our findings suggest that the interaction between age and gap duration should be considered when applying the gap-induced inhibition of the cortical-evoked potential as an objective measure of tinnitus in human subjects. Further studies with tinnitus patients are warranted to identify gap duration that would minimize the effects of age and maximize the difference in the inhibition between those with and without tinnitus.
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Affiliation(s)
- Yunseo Ku
- Department of Biomedical Engineering, College of Medicine, Chungnam National University, Daejeon, Korea
| | - Do Youn Kim
- Interdisciplinary Program in Bioengineering, Graduate School, Seoul National University, Seoul, Korea
| | - Chiheon Kwon
- Interdisciplinary Program in Bioengineering, Graduate School, Seoul National University, Seoul, Korea
| | - Tae Soo Noh
- Department of Otorhinolaryngology- Head and Neck Surgery, Seoul National University Hospital, Seoul, Korea
| | - Moo Kyun Park
- Department of Otorhinolaryngology- Head and Neck Surgery, Seoul National University Hospital, Seoul, Korea
| | - Jun Ho Lee
- Department of Otorhinolaryngology- Head and Neck Surgery, Seoul National University Hospital, Seoul, Korea
| | - Seung Ha Oh
- Department of Otorhinolaryngology- Head and Neck Surgery, Seoul National University Hospital, Seoul, Korea
| | - Hee Chan Kim
- Interdisciplinary Program in Bioengineering, Graduate School, Department of Biomedical Engineering, College of Medicine, Seoul, Korea
- Institute of Medical & Biological Engineering, Medical Research Center, Seoul National University, Seoul, Korea
| | - Myung-Whan Suh
- Department of Otorhinolaryngology- Head and Neck Surgery, Seoul National University Hospital, Seoul, Korea
- * E-mail:
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De Pascalis V, Scacchia P, Sommer K, Checcucci C. Psychopathy traits and reinforcement sensitivity theory: Prepulse inhibition and ERP responses. Biol Psychol 2019; 148:107771. [DOI: 10.1016/j.biopsycho.2019.107771] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 09/09/2019] [Accepted: 09/13/2019] [Indexed: 11/25/2022]
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Martinotti G, Montemitro C, Pettorruso M, Viceconte D, Alessi MC, Di Carlo F, Lucidi L, Picutti E, Santacroce R, Di Giannantonio M. Augmenting pharmacotherapy with neuromodulation techniques for the treatment of bipolar disorder: a focus on the effects of mood stabilizers on cortical excitability. Expert Opin Pharmacother 2019; 20:1575-1588. [PMID: 31150304 DOI: 10.1080/14656566.2019.1622092] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Introduction: Mood stabilizers and antipsychotics have been demonstrated to be effective in Bipolar Disorder, with lithium as the gold standard. However, the presence of adverse events and treatment-resistance is still a relevant issue. To this respect, the use of brain stimulation techniques may be considered as an augmentation strategy, with both Transcranial Magnetic Stimulation (TMS) and Transcranial Direct Current Stimulation (tDCS) having shown some level of efficacy in bipolar patients although clinical trials are still not sufficient to draw any conclusion. Areas covered: The authors have conducted a systematic review of the literature, in order to evaluate the role of mood stabilizers on neural activity and cortical excitability. Furthermore, the article reviews neuromodulation techniques and highlights the potential of integrating pharmacological first-line therapies with these techniques to treat BD patients. Expert opinion: The combination of neuromodulation techniques and available pharmacotherapies is a valuable opportunity which is not undermined by specific effects on cortical excitability and could improve BD patient outcome. Neurostimulation techniques may be considered safer than antidepressant treatments in BD, with a lower level of manic switches and may represent a new treatment strategy in BD depressive episodes.
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Affiliation(s)
- G Martinotti
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti , Chieti , Italy.,Department of Pharmacy, Pharmacology, Clinical Science, University of Hertfordshire , Herts , UK
| | - C Montemitro
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti , Chieti , Italy
| | - M Pettorruso
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti , Chieti , Italy
| | - D Viceconte
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti , Chieti , Italy
| | - M C Alessi
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti , Chieti , Italy
| | - F Di Carlo
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti , Chieti , Italy
| | - L Lucidi
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti , Chieti , Italy
| | - E Picutti
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti , Chieti , Italy
| | - R Santacroce
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti , Chieti , Italy
| | - M Di Giannantonio
- Department of Neuroscience, Imaging and Clinical Sciences, University "G. d'Annunzio" of Chieti , Chieti , Italy
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Notzon S, Vennewald N, Gajewska A, Klahn AL, Diemer J, Winter B, Fohrbeck I, Arolt V, Pauli P, Domschke K, Zwanzger P. Is prepulse modification altered by continuous theta burst stimulation? DAT1 genotype and motor threshold interact on prepulse modification following brain stimulation. Eur Arch Psychiatry Clin Neurosci 2017; 267:767-779. [PMID: 28337537 DOI: 10.1007/s00406-017-0786-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 03/13/2017] [Indexed: 12/14/2022]
Abstract
Previous studies suggest an inhibitory top-down control of the amygdala by the prefrontal cortex (PFC). Both brain regions play a role in the modulation of prepulse modification (PPM) of the acoustic startle response by a pre-stimulus. Repetitive transcranial magnetic stimulation (rTMS) can modulate the activity of the PFC and might thus affect PPM. This study tested the effect of inhibitory rTMS on PPM accounting for a genetic variant of the dopamine transporter gene (DAT1). Healthy participants (N = 102) were stimulated with continuous theta burst stimulation (cTBS, an intense form of inhibitory rTMS) or sham treatment over the right PFC. Afterwards, during continuous presentation of a background white noise a louder noise burst was presented either alone (control startle) or preceded by a prepulse. Participants were genotyped for a DAT1 variable number tandem repeat (VNTR) polymorphism. Two succeeding sessions of cTBS over the right PFC (2 × 600 stimuli with a time lag of 15 min) attenuated averaged prepulse inhibition (PPI) in participants with a high resting motor threshold. An attenuation of PPI induced by prepulses with great distances to the pulse (480, 2000 ms) was observed following active cTBS in participants that were homozygous carriers of the 10-repeat-allele of the DAT1 genotype and had a high resting motor threshold. Our results confirm the importance of the prefrontal cortex for the modulation of PPM. The effects were observed in participants with a high resting motor threshold only, probably because they received a higher dose of cTBS. The effects in homozygous carriers of the DAT1 10-repeat allele confirm the relevance of dopamine for PPM. Conducting an exploratory study we decided against the use of a correction for multiple testing.
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Affiliation(s)
- S Notzon
- Department of Psychiatry and Psychotherapy, University of Münster, Albert-Schweitzer-Campus 1, Gebäude A9, 48149, Münster, Germany.
| | - N Vennewald
- School of Health, Münster University of Applied Sciences, Leonardo Campus 8, 48149, Münster, Germany
| | - A Gajewska
- Department of Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Margarete-Höppel-Platz 1, 97080, Würzburg, Germany
| | - A L Klahn
- Department of Psychiatry and Psychotherapy, University of Münster, Albert-Schweitzer-Campus 1, Gebäude A9, 48149, Münster, Germany
| | - J Diemer
- kbo-Inn-Salzach-Hospital, Gabersee 7, 83512, Wasserburg am Inn, Germany
| | - B Winter
- Catholic University of Applied Sciences North Rhine-Westphalia, Münster, Piusallee 89, 48147, Münster, Germany
| | - I Fohrbeck
- Department of Psychiatry and Psychotherapy, University of Münster, Albert-Schweitzer-Campus 1, Gebäude A9, 48149, Münster, Germany
| | - V Arolt
- Department of Psychiatry and Psychotherapy, University of Münster, Albert-Schweitzer-Campus 1, Gebäude A9, 48149, Münster, Germany
| | - P Pauli
- Department of Biological Psychology, Clinical Psychology and Psychotherapy, University of Würzburg, Marcusstraße 9-11, 97070, Würzburg, Germany
| | - K Domschke
- Department of Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Margarete-Höppel-Platz 1, 97080, Würzburg, Germany
- Department of Psychiatry and Psychotherapy, University of Freiburg, Hauptstrasse 5, 79104, Freiburg, Germany
| | - P Zwanzger
- Department of Psychiatry and Psychotherapy, University of Münster, Albert-Schweitzer-Campus 1, Gebäude A9, 48149, Münster, Germany
- kbo-Inn-Salzach-Hospital, Gabersee 7, 83512, Wasserburg am Inn, Germany
- Department of Psychiatry und Psychotherapy, Ludwig Maximilians University, Munich, Germany
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9
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Ku Y, Ahn JW, Kwon C, Suh MW, Lee JH, Oh SH, Kim HC. Gap prepulse inhibition of the auditory late response in healthy subjects. Psychophysiology 2015; 52:1511-9. [DOI: 10.1111/psyp.12507] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 07/12/2015] [Accepted: 07/15/2015] [Indexed: 01/07/2023]
Affiliation(s)
- Yunseo Ku
- Interdisciplinary Program for Bioengineering; Seoul National University; Seoul Korea
| | - Joong Woo Ahn
- Interdisciplinary Program for Bioengineering; Seoul National University; Seoul Korea
| | - Chiheon Kwon
- Interdisciplinary Program for Bioengineering; Seoul National University; Seoul Korea
| | - Myung-Whan Suh
- Department of Otorhinolaryngology-Head and Neck Surgery; Seoul National University Hospital; Seoul Korea
| | - Jun Ho Lee
- Department of Otorhinolaryngology-Head and Neck Surgery; Seoul National University Hospital; Seoul Korea
- Department of Otorhinolaryngology-Head and Neck Surgery; Seoul National University College of Medicine, Sensory Organ Research Institute, Seoul National University Biomedical Research Institute; Seoul Korea
| | - Seung Ha Oh
- Department of Otorhinolaryngology-Head and Neck Surgery; Seoul National University Hospital; Seoul Korea
- Department of Otorhinolaryngology-Head and Neck Surgery; Seoul National University College of Medicine, Sensory Organ Research Institute, Seoul National University Biomedical Research Institute; Seoul Korea
| | - Hee Chan Kim
- Department of Biomedical Engineering; Medical Research Center, Seoul National University College of Medicine; Seoul Korea
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10
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Csomor PA, Preller KH, Geyer MA, Studerus E, Huber T, Vollenweider FX. Influence of aripiprazole, risperidone, and amisulpride on sensory and sensorimotor gating in healthy 'low and high gating' humans and relation to psychometry. Neuropsychopharmacology 2014; 39:2485-96. [PMID: 24801767 PMCID: PMC4138738 DOI: 10.1038/npp.2014.102] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 04/21/2014] [Accepted: 04/22/2014] [Indexed: 11/09/2022]
Abstract
Despite advances in the treatment of schizophrenia spectrum disorders with atypical antipsychotics (AAPs), there is still need for compounds with improved efficacy/side-effect ratios. Evidence from challenge studies suggests that the assessment of gating functions in humans and rodents with naturally low-gating levels might be a useful model to screen for novel compounds with antipsychotic properties. To further evaluate and extend this translational approach, three AAPs were examined. Compounds without antipsychotic properties served as negative control treatments. In a placebo-controlled, within-subject design, healthy males received either single doses of aripiprazole and risperidone (n=28), amisulpride and lorazepam (n=30), or modafinil and valproate (n=30), and placebo. Prepulse inhibiton (PPI) and P50 suppression were assessed. Clinically associated symptoms were evaluated using the SCL-90-R. Aripiprazole, risperidone, and amisulpride increased P50 suppression in low P50 gaters. Lorazepam, modafinil, and valproate did not influence P50 suppression in low gaters. Furthermore, low P50 gaters scored significantly higher on the SCL-90-R than high P50 gaters. Aripiprazole increased PPI in low PPI gaters, whereas modafinil and lorazepam attenuated PPI in both groups. Risperidone, amisulpride, and valproate did not influence PPI. P50 suppression in low gaters appears to be an antipsychotic-sensitive neurophysiologic marker. This conclusion is supported by the association of low P50 suppression and higher clinically associated scores. Furthermore, PPI might be sensitive for atypical mechanisms of antipsychotic medication. The translational model investigating differential effects of AAPs on gating in healthy subjects with naturally low gating can be beneficial for phase II/III development plans by providing additional information for critical decision making.
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Affiliation(s)
- Philipp A Csomor
- Neuropsychopharmacology and Brain Imaging and Heffter Research Center, Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry, Zürich, Switzerland
| | - Katrin H Preller
- Neuropsychopharmacology and Brain Imaging and Heffter Research Center, Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry, Zürich, Switzerland,Neuropsychopharmacology and Brain Imaging, Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry, Lenngstrasse 31, Zürich 8032, Switzerland, Tel: +41 44 384 26 25, Fax: +41 44 384 24 99, E-mail:
| | - Mark A Geyer
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Erich Studerus
- Neuropsychopharmacology and Brain Imaging and Heffter Research Center, Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry, Zürich, Switzerland,Department of Psychiatry, University of Basel, Basel, Switzerland
| | - Theodor Huber
- Neuropsychopharmacology and Brain Imaging and Heffter Research Center, Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry, Zürich, Switzerland
| | - Franz X Vollenweider
- Neuropsychopharmacology and Brain Imaging and Heffter Research Center, Department of Psychiatry, Psychotherapy and Psychosomatics, University Hospital of Psychiatry, Zürich, Switzerland
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Effects of personality trait emotionality on acoustic startle response and prepulse inhibition including N100 and P200 event-related potential. Clin Neurophysiol 2013; 124:292-305. [DOI: 10.1016/j.clinph.2012.07.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Revised: 07/28/2012] [Accepted: 07/31/2012] [Indexed: 11/18/2022]
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12
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Sensorimotor gating and D2 receptor signalling: evidence from a molecular genetic approach. Int J Neuropsychopharmacol 2012; 15:1427-40. [PMID: 22244514 DOI: 10.1017/s1461145711001787] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Converging evidence from pharmacological investigations, genetic association studies and schizophrenia research indicates an important influence of the dopamine system on sensorimotor gating as measured by prepulse inhibition (PPI) of the acoustic startle response. In particular, D2 receptor agonists have been shown to disrupt PPI in humans and rodents. In the present study, we investigated the associations of two functional DRD2 related single nucleotide polymorphisms (rs4648317 and rs1800497, the latter also known as DRD2/ANKK1 Taq1A) with PPI in two independent healthy human samples (overall n=197; Munich n=101; London n=96). Taq1A is a prominent marker of striatal D2 receptor signalling and was therefore hypothesized to impact on PPI. In line with our hypothesis, we report here reduced PPI levels in individuals with higher striatal D2 receptor signalling as indicated by the Taq1A genotype. Meta-analysis across both samples confirmed this finding. In contrast, an association between rs4648317 and PPI found in the Munich sample could not be confirmed in the London sample. Overall, the present study helps to bridge the gap between pharmacological manipulations of PPI and molecular genetics of the dopaminergic system.
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13
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Schellekens AFA, Mulders PCR, Ellenbroek B, de Jong CAJ, Buitelaar JK, Cools A, Verkes RJ. Early-onset alcohol dependence increases the acoustic startle reflex. Alcohol Clin Exp Res 2012; 36:1075-83. [PMID: 22273252 DOI: 10.1111/j.1530-0277.2011.01700.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 10/19/2011] [Indexed: 11/29/2022]
Abstract
BACKGROUND Hyperreactivity and impaired sensory gating of the acoustic startle response in alcohol dependence has been suggested to reflect a residual effect of previous detoxifications, increasing the severity of subsequent withdrawal episodes. Previous studies on the acoustic startle only included early-onset alcohol-dependent patients. The observed abnormalities may therefore also be specific for this subtype of alcohol dependence. We investigated the acoustic startle response in alcohol-dependent patients and healthy controls and hypothesized that (i) early-onset alcohol-dependent patients show increased acoustic startle responses compared with late-onset alcohol-dependent patients and healthy controls, and (ii) the duration of alcohol dependence or the number of prior detoxifications would not explain the differences in the acoustic startle between early- and late-onset alcohol dependence. METHODS The acoustic startle reflex was assessed in detoxified, male alcohol-dependent patients (N = 83) and age-matched healthy male controls (N = 86). Reflex eye blink responses to an auditory startle stimulus were measured by means of electromyographic recordings over the right orbicularis oculi muscle. Reflex amplitudes and levels of prepulse inhibition (PPI) were analyzed. RESULTS There was no association between number of previous withdrawals and the startle response or PPI. Early-onset alcohol-dependent patients showed higher acoustic startle amplitudes compared with late-onset alcohol-dependent patients and healthy controls [75/105 dB: F(2, 166) = 9.2, p < 0.001; 85/105 dB: F(2, 166) = 12.1, p < 0.001; 95 dB: F(2, 166) = 8.2, p < 0.001; 105 dB: F(2, 166) = 9.7, p < 0.001], and there were no differences in PPI. CONCLUSIONS Increased acoustic startle response in detoxified early-onset alcohol-dependent patients may reflect a trait marker specifically involved in early-onset alcohol dependence. The findings of the current study do not support the hypothesis that the increased startle response is a residual state marker.
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Affiliation(s)
- Arnt F A Schellekens
- Department of Psychiatry, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
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Holstein DH, Csomor PA, Geyer MA, Huber T, Brugger N, Studerus E, Vollenweider FX. The effects of sertindole on sensory gating, sensorimotor gating, and cognition in healthy volunteers. J Psychopharmacol 2011; 25:1600-13. [PMID: 21890590 DOI: 10.1177/0269881111415734] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Sensory gating, indexed by P50 suppression, and sensorimotor gating, indexed by prepulse inhibition (PPI), are impaired in schizophrenia spectrum disorders. There is considerable evidence that schizophrenia patients treated with atypical antipsychotics exhibit relatively less gating deficits than do other patients with schizophrenia. Some recent studies have investigated the effects of antipsychotic medications on gating in healthy volunteers exhibiting low levels of gating, rather than in patients. Therefore, the current study investigated the influence of sertindole versus placebo in two separate experimental sessions, on PPI, P50 suppression, and cognition in 30 male volunteers stratified for low and high baseline gating levels. Sertindole increased PPI and P50 suppression in healthy subjects exhibiting low baseline PPI and low baseline P50 suppression, respectively, while sertindole attenuated gating in subjects exhibiting high baseline gating. Furthermore, subjects exhibiting low PPI chose worse strategies in a spatial working memory task. These findings suggest that mixed D(2)/5-HT(2) receptor antagonists enhance both PPI and P50 suppression in a way that enhances it in healthy subjects exhibiting low baseline gating. Furthermore, the results militate in favor of the concomitant assessment of PPI, P50 suppression and cognitive measures while investigating the effect of antipsychotic medication in healthy subjects.
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The effect of methylphenidate on auditory information processing in healthy volunteers: a combined EEG/MEG study. Psychopharmacology (Berl) 2008; 197:475-86. [PMID: 18264697 DOI: 10.1007/s00213-007-1065-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Accepted: 12/19/2007] [Indexed: 01/09/2023]
Abstract
INTRODUCTION The psychomotor stimulant methylphenidate (MPH) has been shown to improve attentional processes, reflected in behavioural measures such as vigilance, reaction time and visual attention tasks. The neural mechanisms of MPH action on sensory information processing, however, remain poorly understood. To the authors' knowledge, this present study is the first to investigate whether a single dose of MPH affects neural substrates of passive attention in healthy adults studied with simultaneous whole-head magnetoencephalography (MEG) and electroencephalography (EEG). METHODS Monaural left-ear auditory stimuli were presented in an oddball paradigm with infrequent deviant tones differing in frequency and duration. Neuronal activity was recorded with simultaneous whole-head MEG and EEG in 13 healthy subjects (five females; aged 27 +/- 5 years) after oral administration of 40 mg MPH or placebo in a randomised, double-blind, cross-over design. We analysed both electric and magnetic N100, P200 and mismatch negativity (MMN) components. RESULTS MPH increased arousal levels in visual analogue scales. MPH had no effect on the dipole strength of MMN or MMNm in either frequency or duration deviations. MPH did, however, reduce P200 amplitudes in EEG. CONCLUSIONS The lack of effect of MPH on either MMN or MMNm suggests no association between catecholaminergic activities and MMN generation. However, our findings imply that MPH may change the neural bases of auditory information processing such as the early stimulus evaluation reflected in the P200 component. Dopamine and noradrenaline neurotransmitter systems could be responsible for the modulation of these processes. The exclusive effect of MPH on the P200 component could have a clinical application.
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Csomor PA, Stadler RR, Feldon J, Yee BK, Geyer MA, Vollenweider FX. Haloperidol differentially modulates prepulse inhibition and p50 suppression in healthy humans stratified for low and high gating levels. Neuropsychopharmacology 2008; 33:497-512. [PMID: 17460616 DOI: 10.1038/sj.npp.1301421] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Schizophrenia patients exhibit deficits in sensory gating as indexed by reduced prepulse inhibition (PPI) and P50 suppression, which have been linked to psychotic symptom formation and cognitive deficits. Although recent evidence suggests that atypical antipsychotics might be superior over typical antipsychotics in reversing PPI and P50 suppression deficits not only in schizophrenia patients, but also in healthy volunteers exhibiting low levels of PPI, the impact of typical antipsychotics on these gating measures is less clear. To explore the impact of the dopamine D2-like receptor system on gating and cognition, the acute effects of haloperidol on PPI, P50 suppression, and cognition were assessed in 26 healthy male volunteers split into subgroups having low vs high PPI or P50 suppression levels using a placebo-controlled within-subject design. Haloperidol failed to increase PPI in subjects exhibiting low levels of PPI, but attenuated PPI in those subjects with high sensorimotor gating levels. Furthermore, haloperidol increased P50 suppression in subjects exhibiting low P50 gating and disrupted P50 suppression in individuals expressing high P50 gating levels. Independently of drug condition, high PPI levels were associated with superior strategy formation and execution times in a subset of cognitive tests. Moreover, haloperidol impaired spatial working memory performance and planning ability. These findings suggest that dopamine D2-like receptors are critically involved in the modulation of P50 suppression in healthy volunteers, and to a lesser extent also in PPI among subjects expressing high sensorimotor gating levels. Furthermore, the results suggest a relation between sensorimotor gating and working memory performance.
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Affiliation(s)
- Philipp A Csomor
- University Hospital of Psychiatry Zurich, Experimental Psychopathology and Brain Imaging, Zurich, Switzerland
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Samuels ER, Hou RH, Langley RW, Szabadi E, Bradshaw CM. Modulation of the acoustic startle response by the level of arousal: comparison of clonidine and modafinil in healthy volunteers. Neuropsychopharmacology 2007; 32:2405-21. [PMID: 17342169 DOI: 10.1038/sj.npp.1301363] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A sudden loud sound evokes an electromyographic (EMG) response from the orbicularis oculi muscle in humans together with an auditory evoked potential (AEP) and an increase in skin conductance (SC). Startle responses are inhibited by weak prepulses (prepulse inhibition, (PPI)) and may also be modified by the level of alertness. We compared the sedative drug clonidine and the alerting drug modafinil on sound-evoked EMG, AEP, and SC responses, on the PPI of these responses and on level of arousal and autonomic functions. Sixteen healthy male volunteers participated in four weekly sessions (clonidine 0.2 mg, modafinil 400 mg, their combination, placebo) in a double-blind, cross-over, balanced design. Responses were evoked by sound pulses of 115 and 85 dB (PPI) for 40 ms and recorded conventionally. Level of alertness, autonomic functions (pupil diameter, blood pressure, heart rate, salivation, temperature) and the plasma levels of the hormones prolactin, thyroid-stimulating hormone and growth hormone were also measured. Data were analyzed with analysis of variance with multiple comparisons. Both prepulses and clonidine attenuated all three startle responses and modafinil antagonized clonidine's effects on the EMG and AEP responses. None of the drugs affected PPI. Clonidine showed sedative and sympatholytic effects, and modafinil showed alerting and sympathomimetic effects. In conclusion, startle responses were susceptible not only to PPI but also to the level of arousal.
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Affiliation(s)
- Ebony R Samuels
- Division of Psychiatry, Psychopharmacology Section, Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, UK
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18
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Boeijinga PH, Soufflet L, Santoro F, Luthringer R. Ketamine effects on CNS responses assessed with MEG/EEG in a passive auditory sensory-gating paradigm: an attempt for modelling some symptoms of psychosis in man. J Psychopharmacol 2007; 21:321-37. [PMID: 17591659 DOI: 10.1177/0269881107077768] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Disturbances in integrative function have been consistentLy described in psychotic disorder; for instance, prepulse inhibition of the startle reflex (startle-PPI) which is a marker of sensory gating, is deficient in persons with schizophrenia. The N-methyl-D-aspartate antagonist ketamine produces in control subjects a spectrum of neurobehavioural symptoms like encountered in schizophrenia, and disrupts startle-PPI in animals. In the present study, we investigated in 12 healthy subjects whether ketamine would reduce sensory-gating in auditory responses at doses which produce psychotic symptoms. In a double-blind, crossover design loading doses of 0.024, 0.081 and 0.27 mg/kg or saline were employed, followed by maintenance infusion for 120 min. A passive paradigm has been developed which consisted in tone bursts, preceded or not by a (near-threshold) click at intervals of 100 ms or 500 ms. Brain electromagnetic activity imaging of the responses to sound stimuli has been carried out by way of a 148-channel magnetoencephalography-system. Actual evoked response amplitudes and underlying equivalent current dipole strengths have been compared to multi-electrode evoked potentials from the scalp. A click stimulus is capable to inhibit test responses under placebo at the 100 ms interval. During maintenance infusion of ketamine at steady-state (for >30 min) after 0.27 mg/kg, no such amplitude changes were observed anymore (p <0.05) and under these circumstances significant increases in Brief Psychiatric Rating scale and Scale for the Assessment of Negative Symptoms scores were evidenced (p < 0.001). Intermediate effects have been observed when the dose was lowered to 0.081 mg/kg. The present results have shown that ketamine may induce a psychotic-like clinical state associated with gating deficits in healthy subjects.
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Affiliation(s)
- Peter H Boeijinga
- FORENAP - FRP - Institute for Research in Neuroscience, Neuropharmacology and Psychiatry, Rouffach, France. [corrected]
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Abstract
Prepulse inhibition (PPI) of startle is an operational measure of the pre-attentive filtering process known as sensorimotor gating. Originally identified in patients with schizophrenia, PPI deficits have been observed in multiple but not all psychiatric disorders. Thus, as with most signs and symptoms of psychiatric disorders, deficits in PPI cut across diagnostic categories. It remains unclear whether the diversity of disorders exhibiting deficient PPI bespeaks diagnostic overlaps or comorbidities. Given the recent focus on treatments for cognitive deficits of schizophrenia independently of treating psychosis, the relationship of PPI deficits to cognitive deficits becomes of interest. Although PPI cannot be considered to be a cognitive process per se, abnormalities in pre-attentive information processing may be predictive of or lead to complex cognitive deficits. Animal models of PPI deficits produced by dopamine agonists reliably predict existing antipsychotics. Nevertheless, since neither PPI nor cognitive deficits in schizophrenia are ameliorated by standard antipsychotics, current research is exploring the predictive value of non-dopaminergic PPI models in identifying treatments for gating disturbances independently of their relevance to specific disorders. Both PPI and cognitive deficits in schizophrenia patients are not reversed by first generation antipsychotics but may be attenuated by clozapine. Similarly, effects of glutamate antagonists on symptoms in patients and PPI in animals appear to be reduced by clozapine. Hence, treatment-induced reversals of deficits in PPI produced by glutamate antagonists may provide animal, and human, models to aid in the discovery of treatments of cognitive deficits in patients already treated with existing antipsychotics.
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Affiliation(s)
- Mark A Geyer
- Department of Psychiatry, University of California San Diego, La Jolla, CA 92093-0804, USA.
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Oranje B, Gispen-de Wied CC, Westenberg HGM, Kemner C, Verbaten MN, Kahn RS. No effects of l-dopa and bromocriptine on psychophysiological parameters of human selective attention. J Psychopharmacol 2006; 20:789-98. [PMID: 16478755 DOI: 10.1177/0269881106061712] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Patients with schizophrenia exhibit diverse cognitive deficits, one of which is a loss of the ability to focus attention. According to the revised dopamine hypothesis of schizophrenia both an increased mesolimbic and a decreased prefrontal dopaminergic activity is suggested to be involved in schizophrenia. The current study was designed to explore the relationship between dopamine and two psychophysiological parameters of selective attention, i.e. P300 amplitude and processing negativity (PN) in healthy volunteers. In two separate experiments, with a double-blind, balanced and placebo-controlled crossover design, 18 healthy male volunteers were orally administered either 300 mg l-dopa (precursor of dopamine) or placebo (experiment I), or 1.25mg bromocriptine (D2 agonist) or placebo (experiment II). Following this treatment they were tested in an auditory, dichotic selective attention paradigm. An increase in P300 amplitude was found following deviant stimuli when compared to standard stimuli and following attended stimuli when compared to unattended stimuli, regardless of treatment. Similarly, PN was found regardless of treatment. Neither l-dopa nor bromocriptine affected task performance or the amplitudes of PN or P300. In the present study neither l-dopa nor bromocriptine affected PN, P300 amplitude or task performance in healthy controls, phenomena which are usually found to be disrupted in schizophrenia. This indicates that P300 amplitude and PN are neither affected by a global (l-dopa) increased dopaminergic activity, nor by a more selectively towards striatal areas targeted (bromocriptine) increase in dopaminergic activity.
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Affiliation(s)
- B Oranje
- Centre for Neuropsychiatric Schizophrenia Research, Department of Psychiatry, Bispebjerg University Hospital, Copenhagen, Denmark.
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O'Neill BV, Croft RJ, Leung S, Guille V, Galloway M, Phan KL, Nathan PJ. Dopamine receptor stimulation does not modulate the loudness dependence of the auditory evoked potential in humans. Psychopharmacology (Berl) 2006; 188:92-9. [PMID: 16896953 DOI: 10.1007/s00213-006-0501-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Accepted: 06/30/2006] [Indexed: 11/24/2022]
Abstract
RATIONALE The Loudness Dependence of the Auditory Evoked Potential (LDAEP) has been suggested as a reliable measure of central serotonin function in humans; however, its specificity for the serotonin system remains a topic of debate, with possible modulation of this purported serotonin marker by other neurotransmitters, including dopamine. OBJECTIVES We examined the effect of dopaminergic modulation on the LDAEP using the D1/D2/D3 dopamine receptor agonist pergolide and the D2/D3 agonist bromocriptine. METHODS The study was a double-blind, placebo-controlled repeated-measures design in which healthy participants were tested under three acute treatment conditions: placebo, bromocriptine (2.5 mg), and pergolide (0.1 mg). Changes in the amplitude of the N1/P2 at intensities (60, 70, 80, 90, and 100 dB) were examined at C Z. RESULTS Acute stimulation of D1/D2/D3 receptors with pergolide and D2/D3 receptors with bromocriptine in comparison with placebo had no effect on the LDAEP. CONCLUSION These findings indicate that acute stimulation of dopamine D1, D2, and D3 receptors does not modulate the LDAEP in humans. Although the findings suggest that the LDAEP may not be modulated by acute changes in dopamine neurotransmission, further studies are needed to fully characterize its dopaminergic sensitivity.
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Affiliation(s)
- Barry V O'Neill
- Brain Sciences Institute, Swinburne University of Technology, Melbourne, Australia
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22
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Kedzior KK, Koch M, Basar-Eroglu C. Prepulse inhibition (PPI) of auditory startle reflex is associated with PPI of auditory-evoked theta oscillations in healthy humans. Neurosci Lett 2006; 400:246-51. [PMID: 16530955 DOI: 10.1016/j.neulet.2006.02.048] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 02/10/2006] [Accepted: 02/19/2006] [Indexed: 11/20/2022]
Abstract
The aim of the current study was to investigate the auditory-evoked theta oscillatory activity associated with prepulse inhibition (PPI) of the startle reflex in healthy humans. Concurrent electroencephalogram (EEG) and auditory startle reflex were recorded from 19 healthy controls during Pulse-Alone and Prepulse + Pulse trials with 60, 120, and 240 ms prepulse-pulse intervals. Compared to Pulse-Alone trials significant PPI of the startle reflex occurred on all Prepulse + Pulse trials and a significant startle latency reduction occurred on 60 and 120 ms Prepulse + Pulse trials. The largest evoked potentials to auditory stimuli occurred at fronto-central locations. PPI of theta oscillations occurred at frontal, central, and parietal locations. These results suggest that PPI functions not only as sensory-motor gating but also as sensory-cognitive gating since theta oscillations are involved in control of cognitive processes. Absence of significant correlations between PPI of the startle reflex and of theta oscillations at all electrode locations indicates that the two processes may be controlled by different neural mechanisms.
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Affiliation(s)
- Karina Karolina Kedzior
- Institute of Psychology and Cognition Research, University of Bremen, Grazer Str. 4, 28359 Bremen, Germany
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Bitsios P, Giakoumaki SG, Frangou S. The effects of dopamine agonists on prepulse inhibition in healthy men depend on baseline PPI values. Psychopharmacology (Berl) 2005; 182:144-52. [PMID: 16010540 DOI: 10.1007/s00213-005-0056-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Accepted: 04/27/2005] [Indexed: 11/24/2022]
Abstract
RATIONALE AND OBJECTIVES Dopamine (DA) agonists reliably disrupt prepulse inhibition (PPI) of the startle reflex in animals but less so in humans despite cross-species similarities in the neural regulation of PPI. This study examines whether individual variation in baseline PPI may account for the inconsistencies in DA agonist-induced PPI disruption in humans. METHODS Baseline PPI measures were obtained from 32 healthy adult men. Subjects were subsequently tested in three sessions after ingestion of placebo or active drug in a balanced double-blind design. Seventeen subjects were given 0.05 and 0.1 mg of pergolide (a direct DA agonist) and 15 subjects were given 100 and 200 mg of amantadine (an indirect DA agonist). In each treatment group, subjects were assigned to "high" and "low" PPI subgroups based on the median split of their baseline PPI. RESULTS Amantadine and pergolide disrupted PPI in high- but not in low-PPI subjects. In contrast, low-PPI subjects showed a trend towards PPI facilitation especially with pergolide. CONCLUSIONS Our results suggest that baseline PPI is an important determinant of the effect of DA agonists on PPI.
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Affiliation(s)
- Panos Bitsios
- Department of Psychiatry and Behavioural Sciences, Faculty of Medicine, University of Crete, P.O. BOX 2208, Heraklion, 71003, Crete, Greece.
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Scaife JC, Langley RW, Bradshaw CM, Szabadi E. Diazepam suppresses the acquisition but not the expression of 'fear-potentiation' of the acoustic startle response in man. J Psychopharmacol 2005; 19:347-56. [PMID: 15982989 DOI: 10.1177/0269881105053285] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Sudden auditory stimuli elicit a short-latency muscular response (acoustic startle response) which is enhanced during presentation of a Pavlovian conditioned stimulus (CS) that has previously been paired with an aversive unconditioned stimulus (US) ('fear-potentiation'). In rodents, acute treatment with benzodiazepines blocks both the acquisition of fear-potentiation and the expression of fear-potentiation induced by prior exposure to CS/US pairing. We examined the effect of diazepam on the acquisition and expression of fear-potentiation of the acoustic startle response in man. Forty-six male volunteers (18-30 years) participated in two sessions separated by 7 days. In session 1, they were exposed to 20 2-s presentations of a light (CS), 50% of which terminated with an electric shock to the wrist (1.8 mA, 50 ms: US). Somatosensory potentials evoked by the US were recorded from the scalp at Cz, and skin conductance responses from electrodes taped to the second and fourth fingers. In session 2, the CS was presented 20 times without the US; a random 50% of CS presentations terminated with a sound pulse (40-ms 115-dB 1-kHz); an equal number of sound pulses was presented without the CS. Electromyographic responses of the orbicularis oculi muscle to the acoustic stimuli were recorded from electrodes placed on the lower eyelid, late-latency auditory evoked potentials were recorded at Cz, and skin conductance responses from electrodes taped to the second and fourth fingers. In each session, alertness was measured using visual analogue self-rating scales and critical flicker fusion frequency. Subjects received placebo or diazepam 10mg in the two sessions in a double-blind protocol: group 1 (n 12) placebo/placebo; group 2 (n 11) placebo/diazepam; group 3 (n 12) diazepam/placebo; group 4 (n 11) diazepam/diazepam. Diazepam reduced alertness as measured by visual-analogue self-rating scales and critical flicker fusion frequency. In session 1, diazepam reduced the amplitude of the somatosensory potentials and skin conductance responses evoked by the CS. In session 2, the acoustic startle response, the N1/P2 auditory evoked response and the skin conductance response evoked by the sound stimuli were enhanced in the presence of the CS. This fear-potentiation was attenuated in subjects who received diazepam in session 1, but was not affected by the treatment given in session 2. The results indicate that diazepam blocks the acquisition of fear-potentiation of startle responses in man, as in animals, but does not prevent the expression of a previously learned response.
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Affiliation(s)
- J C Scaife
- Psychopharmacology Section, Division of Psychiatry, University of Nottingham, Nottingham, UK
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Oranje B, Gispen-de Wied CC, Westenberg HGM, Kemner C, Verbaten MN, Kahn RS. Increasing dopaminergic activity: effects of L-dopa and bromocriptine on human sensory gating. J Psychopharmacol 2004; 18:388-94. [PMID: 15358983 DOI: 10.1177/026988110401800310] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Schizophrenic patients show a loss of sensory gating, which is reflected in a reduced P50 suppression. Because most of the symptoms in schizophrenia can be reduced by antagonists of the dopaminergic (D2) system, the loss in sensory gating might be related to an increased dopaminergic activity. Therefore, in the present study, the effects of increased dopaminergic neurotransmisson on sensory gating in healthy volunteers were investigated. In a double-blind, balanced, placebo-controlled design, healthy male volunteers were challenged in two separate studies with either 300 mg L-dopa (precursor of dopamine) or placebo (n=16) and 1.25 mg bromocriptine (D2 agonist) or placebo (n=17). Subsequently, they were tested for their sensory gating (P50 suppression). P50 suppression values in the placebo condition were comparable to those found in literature. Although both L-dopa and bromocriptine reduced P50 amplitude, they did so in an equal ratio for both the response to the conditioning (C) and the testing (T) stimuli, therefore not resulting in a reduction of the P50 suppression ratio (T/C). In the present study, neither L-dopa nor bromocriptine reduced sensory gating in healthy volunteers. This suggests that an increased dopaminergic activity in humans is not responsible for the reduction in sensory gating as seen, for example, in schizophrenia.
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Affiliation(s)
- B Oranje
- Center for Neuropsychiatric Schizophrenia Research, Department of Psychiatry afd E, Bispebjerg University Hospital, Copenhagen, Denmark.
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Graham SJ, Scaife JC, Balboa Verduzco AM, Langley RW, Bradshaw CM, Szabadi E. Effects of quetiapine and haloperidol on prepulse inhibition of the acoustic startle (eyeblink) response and the N1/P2 auditory evoked response in man. J Psychopharmacol 2004; 18:173-80. [PMID: 15260904 DOI: 10.1177/0269881104042615] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Contraction of the orbicularis oculi muscle in response to a sudden loud sound (acoustic startle response) and the N1/P2 component of the auditory evoked potential are both attenuated when a brief low-intensity stimulus is presented 30-500 ms before the 'startle-eliciting' stimulus (PPI). Here, we report the effects of the 'atypical' antipsychotic drug quetiapine and the 'conventional' antipsychotic haloperidol on these responses. Sixteen males (aged 19-38 years) participated in four sessions at 7-day intervals, in which they received quetiapine 12.5 mg, quetiapine 25 mg, haloperidol 3 mg and placebo, according to a balanced double-blind design. Electromyographic (EMG) responses of the orbicularis oculi muscle and N1/P2 auditory evoked potentials were recorded in a 20-min session, 2 h after treatment. Subjects received 40 trials in which 1-kHz sounds were presented: (i) 40 ms, 115 dB ('pulse alone' trials) and (ii) 40 ms, 85 dB, followed after 120 ms by 40 ms, 115 dB ('prepulse/pulse' trials). Mean amplitudes of the EMG response and the N1/P2 potential were derived from the pulse-alone trials and, in each case, percentage PPI was calculated. Serum prolactin was measured after each treatment, and autonomic (heart rate, blood pressure, salivation) and psychological (visual analogue self-ratings of mood and alertness, critical flicker fusion frequency) measures were taken before and after each treatment. Quetiapine 12.5 mg and 25 mg significantly reduced the amplitude of the EMG response without altering its inhibition by prepulses; haloperidol had no effect on EMG response amplitude or PPI. Neither drug affected N1/P2 amplitude or PPI of this response. Quetiapine, but not haloperidol, reduced subjective alertness and critical flicker fusion frequency. Haloperidol, but not quetiapine, elevated serum prolactin level. The ability of quetiapine to attenuate the startle response may reflect its sedative action.
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Affiliation(s)
- S J Graham
- Division of Psychiatry, University of Nottingham, Nottingham, UK
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Barrett SL, Bell R, Watson D, King DJ. Effects of amisulpride, risperidone and chlorpromazine on auditory and visual latent inhibition, prepulse inhibition, executive function and eye movements in healthy volunteers. J Psychopharmacol 2004; 18:156-72. [PMID: 15260903 DOI: 10.1177/0269881104042614] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In view of the evidence that cognitive deficits in schizophrenia are critically important for long-term outcome, it is essential to establish the effects that the various antipsychotic compounds have on cognition, particularly second-generation drugs. This parallel group, placebo-controlled study aimed to compare the effects in healthy volunteers (n = 128) of acute doses of the atypical antipsychotics amisulpride (300 mg) and risperidone (3 mg) to those of chlorpromazine (100 mg) on tests thought relevant to the schizophrenic process: auditory and visual latent inhibition, prepulse inhibition of the acoustic startle response, executive function and eye movements. The drugs tested were not found to affect auditory latent inhibition, prepulse inhibition or executive functioning as measured by the Cambridge Neuropsychological Test Battery and the FAS test of verbal fluency. However, risperidone disrupted and amisulpride showed a trend to disrupt visual latent inhibition. Although amisulpride did not affect eye movements, both risperidone and chlorpromazine decreased peak saccadic velocity and increased antisaccade error rates, which, in the risperidone group, correlated with drug-induced akathisia. It was concluded that single doses of these drugs appear to have little effect on cognition, but may affect eye movement parameters in accordance with the amount of sedation and akathisia they produce. The effect risperidone had on latent inhibition is likely to relate to its serotonergic properties. Furthermore, as the trend for disrupted visual latent inhibition following amisulpride was similar in nature to that which would be expected with amphetamine, it was concluded that its behaviour in this model is consistent with its preferential presynaptic dopamine antagonistic activity in low dose and its efficacy in the negative symptoms of schizophrenia.
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Affiliation(s)
- S L Barrett
- Department of Therapeutics and Pharmacology, Queens University Belfast, Belfast, UK.
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Alessi SM, Greenwald M, Johanson CE. The prediction of individual differences in response to D-amphetamine in healthy adults. Behav Pharmacol 2003; 14:19-32. [PMID: 12576878 DOI: 10.1097/00008877-200302000-00002] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Based on previous animal work, the present study investigated whether individual differences in motor activity in a novel environment predicted reinforcing and behaviorally activating effects of D-amphetamine (0, 5, 10 and 20 mg p.o.) in healthy adults. When exposed to a novel environment, 18 participants had high levels of motor activity (high responders; HR) and six had low levels (low responders; LR). These group differences were used to predict effects of D-amphetamine on drug reinforcement, salivary cortisol, motor activity, subjective effects, and acoustic startle reflex in subsequent sessions. Unlike observations in rodents, (1). dose-dependent reinforcing effects of D-amphetamine were evident but without group differences; (2). motor activity was greater in HR but did not vary with D-amphetamine dose; and (3). cortisol levels were not related to the reinforcing effects of D-amphetamine. Startle reflex amplitudes were greater in HR following placebo, but D-amphetamine 20 mg equalized this group difference. There was a trend towards less prepulse inhibition of the acoustic startle reflex in HR compared to LR. LR reported greater overall negative effect following amphetamine administration, but this was not consistently related to dose. Finally, participants with high sensation-seeking personality scores exhibited less prepulse inhibition. The results are discussed in terms of the extant literature.
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Affiliation(s)
- S M Alessi
- University of Connecticut Health Center, Farmington, Connecticut 06030, USA.
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Graham SJ, Langley RW, Balboa VAM, Bradshaw CM, Szabadi E. Effects of ketanserin and haloperidol on prepulse inhibition of the acoustic startle (eyeblink) response and the N1/P2 auditory evoked response in man. J Psychopharmacol 2002; 16:15-22. [PMID: 11949767 DOI: 10.1177/026988110201600101] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Contraction of the orbicularis oculi muscle in response to a sudden loud sound (acoustic startle response) and the N1/P2 component of the auditory evoked potential are both attenuated when a brief low-intensity stimulus is presented 30-500 ms before the 'startle-eliciting' stimulus (prepulse inhibition). Here, we report the effects of the serotonin (5-HT)2 receptor antagonist ketanserin and the D2 dopamine receptor blocking antipsychotic drug haloperidol on these responses. Fifteen males (aged 18-35 years) participated in four sessions at 7-day intervals, in which they received ketanserin 20 mg, ketanserin 40 mg, haloperidol 3 mg and placebo, according to a balanced double-blind design. Electromyographic (EMG) responses of the orbicularis oculi muscle and N1/P2 auditory evoked potentials were recorded in a 20-min session, 3 h after ingestion of haloperidol or 1 h after ingestion of ketanserin. Subjects received 40 trials in which 1-kHz sounds were presented: (i) 40 ms, 115 dB ('pulse alone' trials), and (ii) 40 ms, 85 dB, followed after 120 ms by 40 ms, 115 dB ('prepulse/pulse' trials). Mean amplitudes of the EMG response and the N1/P2 potential were derived from the pulse-alone trials and, in each case, percentage prepulse inhibition was calculated. Serum prolactin was measured after each treatment, and autonomic (heart rate, blood pressure, salivation) and psychological (visual analogue self-ratings of mood and alertness, critical flicker fusion frequency) measures were taken before and after each treatment. Ketanserin 40 mg significantly reduced the amplitude of the EMG response and both doses of ketanserin significantly suppressed prepulse inhibition of the response; haloperidol had no effect on EMG response amplitude or prepulse inhibition. Neither drug affected N1/P2 amplitude or prepulse inhibition of this response. Ketanserin, but not haloperidol, reduced subjective alertness and critical flicker fusion frequency. Haloperidol, but not ketanserin, elevated serum prolactin level. These results confirm that prepulse inhibition of the startle response and of the N1/P2 complex have different pharmacological sensitivities. The ability of ketanserin to attenuate the startle response may reflect its sedative action, as other drugs with sedative properties have also been found to attenuate the startle response in man. The ability of ketanserin to suppress prepulse inhibition of the startle response is consistent with previous evidence for the involvement of 5-HTergic mechanisms in the regulation of prepulse inhibition in man.
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Affiliation(s)
- S J Graham
- Division of Psychiatry, University of Nottingham, UK
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Nielsen DM, Derber WJ, McClellan DA, Crnic LS. Alterations in the auditory startle response in Fmr1 targeted mutant mouse models of fragile X syndrome. Brain Res 2002; 927:8-17. [PMID: 11814427 DOI: 10.1016/s0006-8993(01)03309-1] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Fragile X syndrome results from inadequate production of the fragile X mental retardation protein (FMRP). Mice with a mutation targeted to the Fmr1 gene lack FMRP and thus are a valuable animal model for studying the behavioral and neural phenotype of this human disorder. Mice of two genetic backgrounds containing the Fmr1 mutation, C57BL/6J (C57-KO) and an F1 hybrid (C57BL/6J mutant x FVB/NJ; F1-KO) did not differ from control mice in behavior in the elevated plus maze or the open field. Both the C57-KO and F1-KO mice exhibited greater startle responses than normal mice to low intensity (80 dB) white noise bursts and decreased responses to high intensity (120 dB) white noise bursts. These behavioral alterations appear to be specific to the Fmr1 mutation since they are present on both genetic backgrounds. Furthermore, the mice lacking FMRP resemble individuals with fragile X syndrome in their increased sensitivity to low intensity auditory stimuli. These findings should prove useful in determining how the absence of FMRP alters the brain and behavior, and in testing potential treatments for fragile X syndrome.
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Affiliation(s)
- Darci M Nielsen
- Department of Pediatrics, C-233, University of Colorado School of Medicine, 4200 E. 9th Ave., Denver, CO 80262, USA.
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Pekkone E, Hirvonen J, Ahveninen J, Kähkönen S, Kaakkola S, Huttunen J, Jääskeläinen IP. Memory-based comparison process not attenuated by haloperidol: a combined MEG and EEG study. Neuroreport 2002; 13:177-81. [PMID: 11924884 DOI: 10.1097/00001756-200201210-00040] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Auditory P50 and N100 responses reflect preattentive processing, whereas subsequent mismatch negativity (MMN) response indexes memory-based comparison process. Divergent ERP responses have been found in schizophrenia and in Parkinson's disease (PD), which have abnormalities in cerebral dopamine activity. We used simultaneously magnetoencephalography and electroencephalography to investigate, whether a single dose of haloperidol, a dopamine D2-receptor antagonist, modulates preattentive auditory processing using a randomized, double-blind, placebo-controlled crossover design. Our results showed that haloperidol did not alter MMN to frequency and duration changes, whereas the magnetic MMN to frequency change was significantly accelerated. The amplitude and latency changes of the electric and magnetic P50 and N100 were insignificant. Our results indicate that memory-based sound comparison and preceding cortical processing underlying stimulus detection are not attenuated by haloperidol, whereas haloperidol appears to accelerate preattentive sound comparison.
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Affiliation(s)
- Eero Pekkone
- Department of Neurology, Medical Engineering Centre, Helsinki University Central Hospital, Finland
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Abduljawad KA, Langley RW, Bradshaw CM, Szabadi E. Effects of clonidine and diazepam on prepulse inhibition of the acoustic startle response and the N1/P2 auditory evoked potential in man. J Psychopharmacol 2001; 15:237-42. [PMID: 11769816 DOI: 10.1177/026988110101500402] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Contraction of the orbicularis oculi muscle in response to a sudden loud sound (acoustic startle response) and the N1/P2 component of the auditory evoked potential are both attenuated when a brief low-intensity stimulus is presented 30-500 ms before the 'startle-eliciting' stimulus (prepulse inhibition). We examined the effects of two sedative/anxiolytic drugs, diazepam and clonidine, on prepulse inhibition of these two responses in healthy volunteers. Fifteen males (aged 18-35 years) participated in three sessions in which they received oral doses of placebo, diazepam 10 mg and clonidine 0.2 mg according to a balanced double-blind protocol. Thirty-minute simultaneous recordings of the electromyographic (EMG) responses of the orbicularis oculi muscle of the right eye and the vertex auditory evoked potentials took place 120 min after ingestion of clonidine and 60 min after ingestion of diazepam. Sound stimuli (1 kHz) were presented in 60 trials separated by variable intervals (mean 25 s): (i) 40-ms 115-dB ('pulse alone', 20 trials); (ii) 40-ms 85-dB (20 trials); (iii) 40-ms 85-dB, followed after 120 ms by 40-ms 115-dB ('prepulse/pulse', 20 trials). Mean amplitudes of the EMG response and the N1/P2 potential were derived from the pulse-alone trials and, in each case, percentage prepulse inhibition was calculated. The amplitude of the EMG response was significantly reduced both by diazepam and by clonidine; neither drug significantly altered prepulse inhibition of the EMG response. Diazepam, but not clonidine, significantly reduced the amplitude of the N1/P2 potential; neither drug significantly affected prepulse inhibition of the N1/P2 potential. Both drugs reduced self-rated alertness and anxiety, and systolic blood pressure; clonidine, but not diazepam reduced diastolic blood pressure and salivation. The results confirm previous findings that sedative drugs can suppress the startle response without affecting prepulse inhibition of this response, and provide new information on the effects of these drugs on the N1/P2 potential and its inhibition by prepulses.
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Graham SJ, Langley RW, Bradshaw CM, Szabadi E. Effects of haloperidol and clozapine on prepulse inhibition of the acoustic startle response and the N1/P2 auditory evoked potential in man. J Psychopharmacol 2001; 15:243-50. [PMID: 11769817 DOI: 10.1177/026988110101500411] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Contraction of the orbicularis oculi muscle in response to a sudden loud sound (acoustic startle response) and the N1/P2 component of the auditory evoked potential are both attenuated when a brief low-intensity stimulus is presented 30-500 ms before the 'startle-eliciting' stimulus (prepulse inhibition). Here, we report the effects of the 'conventional' antipsychotic drug haloperidol and the 'atypical' antipsychotic clozapine on these responses. Fifteen males (aged 19-54 years) participated in four sessions at 7-day intervals, in which they received clozapine 3 mg, clozapine 6 mg, haloperidol 3 mg and placebo, according to a balanced double-blind design. Electromyographic (EMG) responses of the orbicularis oculi muscle and N1/P2 auditory evoked potentials were recorded in a 20-min session, 3 h after treatment. Subjects received 40 trials in which 1-kHz sounds were presented: (i) 40 ms, 115 dB ('pulse alone' trials) and (ii) 40 ms, 85 dB, followed after 120 ms by 40 ms, 115 dB ('prepulse/pulse' trials). Mean amplitudes of the EMG response and the N1/P2 potential were derived from the pulse-alone trials and, in each case, percentage prepulse inhibition was calculated. Serum prolactin was measured after each treatment, and autonomic (heart rate, blood pressure, salivation) and psychological (visual analogue self-ratings of mood and alertness, critical flicker fusion frequency) measures were taken before and after each treatment. Clozapine 6 mg significantly reduced the amplitude of the EMG response without altering its inhibition by prepulses. Clozapine 6 mg did not affect the amplitude of the N1/P2 potential, but significantly attenuated prepulse inhibition of that response. Clozapine 3 mg and haloperidol had no significant effect on either response. Clozapine 3 mg and 6 mg, but not haloperidol, reduced subjective alertness and critical flicker fusion frequency. Clozapine 6 mg reduced salivation. Haloperidol, but not clozapine, elevated serum prolactin levels. These results confirm that prepulse inhibition of the startle response and of the N1/P2 complex have different pharmacological sensitivities. The abililty of clozapine to attenuate the startle response may reflect its sedative action. The basis of the abililty of clozapine to suppress prepulse inhibition of the N1/P2 potential remains uncertain.
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Affiliation(s)
- S J Graham
- Division of Psychiatry, University of Nottingham, UK
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Pretorius JL, Phillips M, Langley RW, Szabadi E, Bradshaw CM. Comparison of clozapine and haloperidol on some autonomic and psychomotor functions, and on serum prolactin concentration, in healthy subjects. Br J Clin Pharmacol 2001; 52:322-6. [PMID: 11560566 PMCID: PMC2014537 DOI: 10.1046/j.0306-5251.2001.01448.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AIMS To compare the autonomic, neuroendocrine and psychomotor effects of single doses of the 'atypical' antipsychotic clozapine and the 'classical' antipsychotic haloperidol, in healthy male volunteers. METHODS Clozapine (50 mg), haloperidol (3 mg) and placebo were administered to 12 healthy male volunteers at weekly intervals, according to a balanced double-blind design. Resting pupil diameter, salivary output, heart rate, blood pressure, plasma prolactin concentration, critical flicker fusion frequency and subjective 'alertness', 'contentedness' and 'anxiety' were measured at baseline and 2, 3, 4 and 5 h after drug ingestion. Data were analysed by analysis of variance with individual comparisons (Dunnett's test) with a significance criterion of P < 0.05. RESULTS Significant treatment effects (difference from placebo [mean, 95% CI] 5 h after drug ingestion) were as follows: clozapine reduced pupil diameter (mm; -3.02 [-3.56, -2.47]), salivary output (g; -0.34 [-0.60, -0.08]), mean arterial blood pressure (mm Hg; -8.7 [-14.3, -3.1]), critical flicker fusion frequency (Hz; -3.26 [-3.94, -2.58]), and subjectively-rated 'alertness' (mm; -20.94 [-29.21, -12.67]) and 'contentedness' (mm; -12.98 [-17.90, -8.06]), whereas haloperidol increased prolactin concentration (mU l(-1); 301.3 [196.7, 405.8]) and caused small reductions in pupil diameter (mm; -0.68 [-1.23, -0.14]), mean arterial blood pressure (mm Hg; -7.0 [-12.6, -1.4]) and critical flicker fusion frequency (Hz; -1.15 [-1.83, -0.47]). CONCLUSIONS The effects of the antipsychotics are in agreement with their receptor binding profiles: alpha(1)-adrenoceptor blockade by clozapine may contribute to reductions in pupil diameter, salivation, mean arterial blood pressure and sedation, and muscarinic cholinoceptor blockade by the drug may underlie the reduction in salivation. Conversely, D(2) dopamine receptor blockade by haloperidol is likely to be responsible for the increase in prolactin secretion evoked by the drug.
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Affiliation(s)
- J L Pretorius
- Division of Psychiatry, University of Nottingham, University Hospital, Queen's Medical Centre, Nottingham NG7 2UH, UK
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Kähkönen S, Ahveninen J, Pekkonen E, Kaakkola S, Huttunen J, Peltonen T, Ilmoniemi RJ, Jääskeläinen IP. No evidence for dependence of early cortical auditory processing on dopamine D(2)-receptor modulation: a whole-head magnetoencephalographic study. Psychiatry Res 2001; 107:117-23. [PMID: 11530277 DOI: 10.1016/s0925-4927(01)00096-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Magnetoencephalography (MEG) was used to determine the effect of neuroleptic challenge on brain responses in healthy subjects. In a double-blind, randomized, placebo-controlled, cross-over design study, the dopamine D(2) receptor antagonist haloperidol (2 mg) was given orally to 12 healthy volunteers. The middle-latency auditory evoked magnetic fields (MAEF) were recorded 3 h after administration of haloperidol or placebo with a whole-head 122-channel MEG. Haloperidol did not significantly affect MAEF responses. The dipole moments and source locations of the responses were not significantly influenced by haloperidol. These results suggest that dopamine D(2) receptors are not involved in the early phases of auditory cortical processing.
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Affiliation(s)
- S Kähkönen
- BioMag Laboratory, Medical Engineering Centre, Helsinki University Central Hospital, P.O. Box 340, FIN-00029 Helsinki, Finland.
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Phillips MA, Oxtoby EK, Langley RW, Bradshaw CM, Szabadi E. Effects of acute tryptophan depletion on prepulse inhibition of the acoustic startle (eyeblink) response and the N1/P2 auditory evoked response in man. J Psychopharmacol 2001; 14:258-65. [PMID: 11106305 DOI: 10.1177/026988110001400308] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Contraction of the orbicularis oculi muscle in response to a sudden loud sound (acoustic startle response) and the N1/P2 component of the auditory evoked potential are both attenuated when a brief low-intensity stimulus is presented 30-500 ms before the 'startle-eliciting' stimulus (prepulse inhibition). Here, we report the effect of acute tryptophan depletion on prepulse inhibition of these responses. Thirteen males (21-52 years) participated in two sessions separated by 7 days, in which they ingested a drink containing a mixture of amino-acids, which either included (+ TP) or did not include (- TP) tryptophan, according to a balanced double-blind design. Electromyographic (EMG) responses of the orbicularis oculi muscle and N1/P2 auditory evoked potentials were recorded in a 20-min session, 6 h after ingestion of the mixture. Subjects received 40 trials in which 1-kHz sounds were presented: (i) 40 ms, 115 dB ('pulse alone' trials) and (ii) 40 ms, 85 dB, followed after 120 ms by 40 ms, 115 dB ('prepulse/pulse' trials). Mean amplitudes of the EMG response and the N1/P2 potential were derived from the pulse-alone trials and, in each case, percentage prepulse inhibition was calculated. Plasma tryptophan levels were measured from blood samples taken before and 7 h after each treatment. Under the + TP condition, both the EMG response and the N1/P2 complex showed > 60% prepulse inhibition. The - TP condition was associated with (i) significant suppression of prepulse inhibition of the EMG response, with no significant change in response amplitude and (ii) reduction of the amplitude of the N1/P2 potential, with no significant change in prepulse inhibition of this response. Tryptophan levels rose by 90+/-15% under the + TP condition and fell by 81+/-3% under the - TP condition. The suppression of prepulse inhibition of the acoustic startle response under the - TP condition suggests that central 5-hydroxytryptaminergic mechanisms may be involved in regulating prepulse inhibition of this response. The lack of effect of tryptophan depletion on prepulse inhibition of the N1/P2 potential suggests that different mechanisms are involved in prepulse inhibition of the startle response and the N1/P2 complex.
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Affiliation(s)
- M A Phillips
- Division of Psychiatry, University of Nottingham, UK
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Abstract
Prepulse inhibition (PPI) of the acoustic startle reflex is a measure of sensorimotor gating which occurs in both rodents and humans. PPI is deficient in severe neuropsychiatric disorders such as schizophrenia. We investigated PPI in 10 adult monkeys (Cebus apella). Stimuli were 115 dB white noise startle pulses, either alone or preceded by 120 ms with a prepulse of either 8 or 16 dB above the 70 dB background noise. Experiments included a pretreatment baseline session and a session following treatment with either phencyclidine (PCP, 0.12 mg/kg, i.m.) or saline. Comparison of peak amplitudes indicated a significant intensity-dependent decrease in startle response that was similar to that observed in humans under similar experimental conditions. PCP treatment significantly disrupted PPI, but did not reduce responses to startle pulses alone. These results provide the first demonstration of PPI in monkeys. The ability of PCP to induce schizophrenia-like deficits in PPI suggests that PPI in nonhuman primates may provide an important animal model for the development of novel anti-schizophrenia medications.
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Affiliation(s)
- G S Linn
- The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
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Phillips MA, Langley RW, Bradshaw CM, Szabadi E. The effects of some antidepressant drugs on prepulse inhibition of the acoustic startle (eyeblink) response and the N1/P2 auditory evoked response in man. J Psychopharmacol 2000; 14:40-5. [PMID: 10757252 DOI: 10.1177/026988110001400105] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Both the acoustic startle (eyeblink) response and the N1/P2 complex of the auditory evoked potential can be suppressed by presentation of a brief low-intensity stimulus 30-500 ms before the 'startle-eliciting' stimulus ('prepulse inhibition', PPI). We examined the effects of three antidepressants on PPI of these two responses. Fifteen males (19-30 years) participated in four weekly sessions, in which they received placebo, amitriptyline (100 mg), fluvoxamine (100 mg), and reboxetine (4 mg) (p.o.), according to a balanced double-blind design. Twenty minute simultaneous recordings of electromyographic (EMG) responses of the orbicularis oculi muscle of the right eye and vertex auditory evoked potentials were carried out 195 min after drug ingestion. Sound stimuli (1 kHz) were presented in 40 trials separated by variable intervals (mean 25 s): (1) 40 ms, 115 dB ('pulse alone', 20 trials) and (2) 40 ms, 85 dB, followed after 120 ms by 40 ms, 115 dB ('prepulse/pulse', 20 trials). Under the placebo condition, both the EMG response and the N1/P2 complex showed >50% PPI. Fluvoxamine and reboxetine did not significantly alter the amplitude or PPI of either response. Amitriptyline significantly reduced the amplitudes of both responses; it had no effect on PPI of the EMG response, but significantly attenuated PPI of the N1/P2 complex. Amitriptyline also reduced arousal, as indicated by an increase in power of low-frequency electroencephalographic waves. The results confirm the susceptibility of the N1/P2 complex to PPI. The reduction of the amplitudes of the EMG response and N1/P2 complex by amitriptyline may be related to its sedative action. The differential effect of amitriptyline on PPI of the N1/P2 complex supports the suggestion that different mechanisms may be involved in PPI of this response and PPI of the N1/P2 complex.
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Affiliation(s)
- M A Phillips
- Division of Psychiatry, University of Nottingham, UK
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